Defoaming method and means



I Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE Harland H. Young, 'Jr.,

Chicago, Ill... assignor to Industrial Patents Corporation, Chicago, 111., a corporation of Delaware N Drawing. Application July 9, 1935, Serial No. 30,577

Claims.

This invention relates to the prevention of foaming or frothing in the preparation or use of solutions, suspensions or mixtures of various kinds which have a tendency to produce foam 5 or froth.

One of the objects of this invention is to provide an improved defoamer which may be added to such material as glue to prevent foaming when the glue is used as it normally is used in aqueous solutions.

Other objects of the invention will be apparent from the description and claims which follow. It is lmown that water insoluble metallic soaps are more or less efiective as defoamers when the metallic soap is dissolved in an organic solvent such as paraflin or tallow and a dispersing agent such as sulphonated oilor sulphonalted tallow is added. It is also known that some deioaming effeet is secured by the use of a water insoluble 29 metallic soap dissolved in an organic solvent such as pine oil. I

The present invention is directed to an unusually efiective deioamer which is inexpensive to prepare. The defoamer of the present invention is prepared by first dissolving aluminum stearate in free steeric acid. The solution is sub= sequently diluted with para and the result= ing was: is then emulsified with the glue or other mixture from which it is desired to remove the foaming characteristic.

An example of a suitable formula is as follows:

Fifteen parts ofv aluminum stearate are dissolved in 90 to 100 parts of stearic acid and to this solution are added90 pounds of parafin wax and 100 pounds of Japan wax. This wax isthen made up into the defoamer as follows: pounds of wax are dissolved in 135 pounds of tallow, so

pounds of castor oil, and, 30 pounds of whey" red oil. This solution is then emulsified with 30 to pounds .of water in which form it is ready for use.

Although trivalent aluminum is known to form only the monoand di-stearate and not the tri- 5 stearate, I find that by using a quantity of stearic acid which approximates the quantity necessary to convert a di-stearate to a tri-stearate, the resulting defoamer is unusually effective and not only has greatly increased defoaming power but 10 also inhibits separation of a scum of aluminum stearate on the surface of glue to which the defoamer has been added.

As used in this specification and in the claims, the term solution" will be understood in its 15 broad sense as including true soluti0ns,'suspensoids, and colloids.

I cl:

1. A defoamed product consisting of a mixture of a foable substance capable of aqueous 20 solution, and a deioamer comprising aluminum stearate, stearic acid and wax dispersed in the ioamable substance.

2. A defoamed product comprising a mixture of a foamable substance capable of aqueous soiu- 25 tion, and a defoamer comprising aluminum stearate and stearic acid.

3. A deioamer comprising wax, stearate and stearic acid.

4. The process of preparing a defng agent 30 which comprises dissolving aluminum stearate in stearic acid and thereafter diluting the solution with paramn wax.

5. The process of preparing, a defoaming agent which comprises dissolving aluminum stearate in 5 stearic acid and. thereafter diluting the solution with wax.

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': i Qili YOUNG, Jn. 

